The popular houseplant genus Tradescantia, often called wandering dude, inch plant, or spiderwort, is generally considered mildly toxic to both humans and pets. The primary danger stems from physical irritation rather than severe, systemic poisoning. Exposure incidents usually lead to uncomfortable symptoms that are rarely life-threatening, but caution is appropriate.
The Mechanism of Tradescantia Skin Irritation
The irritant effect of Tradescantia on the skin is due to microscopic, needle-like structures within the plant’s cells. These structures are known as raphides, which are insoluble calcium oxalate crystals. When the plant tissue is broken or chewed, the pressure causes these tiny, sharp crystals to be ejected. The mechanical action of the crystals piercing the skin or mucous membranes creates an immediate, painful reaction.
The physical irritation from the raphides triggers a defensive response, including the release of histamine, leading to contact dermatitis. Symptoms in humans and pets include redness, intense itching, swelling, and sometimes the formation of blisters or pustules at the contact site. This reaction is common in dogs with thin skin, such as on the abdomen, groin, armpits, and paws.
Simple handling of the plant, such as watering or light pruning, typically poses a low risk for humans, unless the sap contacts sensitive skin or open cuts. Breaking stems releases sap, increasing the likelihood of developing a localized rash. For pets, repeated or prolonged contact can lead to chronic skin inflammation requiring veterinary intervention.
Ingestion Risks for Pets and Humans
Ingesting Tradescantia presents risks primarily impacting the gastrointestinal tract due to the calcium oxalate crystals. When the leaves or stems are chewed, the raphides embed themselves into the delicate tissues of the mouth, throat, and esophagus. This piercing action causes immediate pain and discomfort, which often prevents the consumption of a dangerous amount.
In pets, common symptoms following ingestion include excessive drooling, pawing at the mouth due to oral pain, and difficulty swallowing. The irritation often leads to vomiting and general stomach upset as the crystals travel down the digestive tract. While the plant is rarely associated with fatal poisoning, gastrointestinal distress can range from mild nausea to significant discomfort requiring supportive care. The ASPCA lists various Tradescantia species as toxic to dogs, cats, and horses.
For human children, the risk is similar to pets, with the primary concern being oral irritation leading to immediate rejection of the plant material. Eating a small amount typically causes a burning sensation in the mouth and throat, which can be accompanied by nausea and vomiting. Because the toxicity is based on physical irritation, the effects are usually localized and temporary.
Immediate Steps Following Exposure
A prompt response to any exposure can minimize discomfort and prevent severe reactions. If skin contact occurs with the plant’s sap, wash the affected area thoroughly with mild soap and lukewarm running water for at least 15 minutes. This action helps dislodge and rinse away the irritating calcium oxalate crystals.
For pets showing signs of contact dermatitis, such as redness, itching, or rash, bathing the area with a gentle, soothing cleanser can provide relief. If the irritation persists, worsens, or if the pet develops secondary infections from excessive scratching, a visit to the veterinarian is necessary for prescription topical or oral anti-inflammatories.
If you suspect a pet or child has eaten Tradescantia material, the immediate priority is to contact a professional for guidance. Call a veterinarian, the ASPCA Animal Poison Control Center, or Human Poison Control immediately. Be ready to provide the specific plant species, the estimated quantity consumed, and the time elapsed since the ingestion occurred.
Do not attempt to induce vomiting unless specifically instructed by a medical or poison control professional, as this can cause more harm. To prevent future incidents, place all houseplants on high shelves or in hanging planters, out of the reach of pets and children. Wearing gloves when pruning or repotting Tradescantia is an effective way to protect your skin from the irritating sap.